Automated assembly systems have greatly improved the quality of manufactured products as well as the efficiency with which those products are made. These systems generally include a conveyor system that is controlled by a central computer. The central computer directs the conveyor system to move a product to successive work stations in order to accomplish a variety of operations on the product, such as loading, assembly, testing, rejecting, and unloading of the product.
Each work station typically includes an automated device for accomplishing a particular operation on the product. Typically, the majority of the operation of each device is directly controlled by the central computer. The central computer typically must be programmed with a very complex operating program that enables the computer to direct the operations of each individual work station device. The program may include the operating parameters and instructions for operating each device, code enabling the computer to communicate with each device, and a complex code structure interrelating the operation of each device to that of other devices in the system.
In smaller industrial applications, the central computer is typically directly wired to each work station, leading to a very complex web of connections. In larger industrial assembly systems, the central computer may communicate to each device through a network bus structure. In either application, each device is identified by a device address or network address. Therefore, each individual device must be programmed with an identifying address. If a device is removed from a network or its location in the assembly system is changed, that device must be reprogrammed with a new address identifiable to the central computer. In this manner, the central computer knows the individual location of each device and can direct the operations of each device individually.
Automated assembly systems such as just described are not easily modified and often are special purpose systems, i.e., they are only capable of assembling a single product or family of products. Significant changes to the automated assembly system require major reprogramming efforts for the central computer and any work station devices. These limitations produce a rather inflexible automation system that does not easily expand with a business or afford a business the ability to manufacture different products on the same assembly line. Further, it should be apparent that modifications to these automated systems require significant down time for the assembly system which in turn leads to costly production gaps. These systems also do not easily allow for reduced production during production cut-backs. Therefore, there is currently a need for a modular automated assembly system that is both cost effective, highly flexible, and easily adaptable.